May 92 - GRAPHICAL TRUFFLES
GRAPHICAL TRUFFLES
MULTIPLE SCREENS REVEALED
FORREST TANAKA AND BILL GUSCHWAN
One very neat feature of the Macintosh is that you can connect more than one screen to
the computer and use them as if they were one big screen. Better still, applications
take advantage of multiple screens automatically. But the screens that are attached to
your system can have different sizes, depths, and color tables, and you might want to
optimize your application for each screen, or you might want to find the best screen to
display something on. Both these things are easy to do, but not necessarily in the ways
that you might think at first. In this column, we'll uncover a few important truths
about QuickDraw's handling of multiple screens, and we'll talk about a few ways to deal
with multiple screens if you want to go beyond what QuickDraw gives you for free.
It's important to understand that if you're just drawing items to a window and want to
stay completely above the specifics of different screens, don't do anything
special--just draw to your window as if there were one screen. QuickDraw was